This invention relates to key-cutting machines, particularly to machines for cutting flat key blade blanks to provide longitudinal tumbler-receiving recesses therein. More particularly, the invention relates to a machine for cutting flat keys for cylinder locks having coplanar lock tumblers, which keys are of the type disclosed in copending U.S. patent application Ser. No. 685,595, filed on Dec. 24 1984, as continuation of application Ser. No. 360,886, filed on Mar. 23, 1982.
The key of the foregoing application is provided with tumbler-receiving recesses, which extend longitudinally in each side of the blade from a distal end thereof. Transverse shoulders formed at the inner ends of the recesses provide bittings on the key blade, for engagement with the ends of longitudinally movable coplanar lock tumblers. Each recess and its associated bitting is formed in the blade by a cutting process, which removes material from a suitable blade blank.
Heretofore, key-cutting machines have been provided, for making tubular keys for cylinder locks. The machines form longitudinally extending recesses in tubular blanks, by a cutting process, and the recesses terminate in shoulders providing bittings that engage the ends of longitudinally movable lock tumblers. Such machines are disclosed in U.S. Pat. Nos. 1,978,009, 2,129,087, 3,418,882, 3,495,482, 3,818,798, 4,022,107, and 4,203,693. The prior machines are not adapted for cutting flatbladed keys, so that a need exists for such a machine.